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Home / Equine Research Bank / Can J Vet Res / Clinical signs, laboratory changes and toxicokinetics of bro...
Canadian journal of veterinary research = Revue canadienne de recherche veterinaire1991; 55(1); 21-27;

Clinical signs, laboratory changes and toxicokinetics of brodifacoum in the horse.

Abstract: Six horses gavaged with a commercial brodifacoum (BDF)-containing bait (Talone) at a dosage of 0.125 mg of BDF/kg of body weight showed weight loss, severe hypocoagulability and hemogram alterations. Four of the horses became depressed and anorectic; one required vitamin K1 therapy. Increases in clotting times were observed at 24 h in the partial thromboplastin time (PTT) followed by the thrombotest (TBT) and one-stage prothrombin time (PT) at 48 h. Elevated mean PTT, PT and TBT were observed from days 4 to 8 (p less than 0.05) with levels returning to pretreatment levels by day 12. Maximum prolongation was a fourfold increase in PTT (day 4), a 2.5-fold increase in TBT (day 6) and a twofold increase in PT (day 6). Thrombin clotting times remained unchanged. In two horses prolongation in clotting time did not normalize until day 23. The mean hematocrit (0.38 +/- 0.01 L/L) was decreased (p less than 0.05) from day 8 (0.33 +/- 0.02 L/L) to day 14 (0.33 +/- 0.01 L/L). The hemoglobin concentration and erythrocyte numbers were decreased (p less than 0.05) from day 6 (20.1%, 17.6% respectively) to day 14 (22%, 20% respectively). Platelet counts decreased on day 6 (17.2%) to nine (14.6%). No other significant changes were observed in routine hematological and serum biochemical parameters. Peak plasma concentrations of BDF occurred 2 to 3 h after oral administration; two horses had detectable levels of BDF at nine days. Pharmacokinetic evaluation indicated that BDF has a half-life of 1.22 +/- 0.22 days, a body clearance of 1073.1 +/- 53.21 mL/kg/day, a volume of distribution of 1853.7 +/- 26.41 ng-day/mL and closely approximates a one-compartment model in the elimination phase.(ABSTRACT TRUNCATED AT 250 WORDS)
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Publication Date: 1991-01-01 PubMed ID: 1884280PubMed Central: PMC1263408
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  • Journal Article
  • Research Support
  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This study investigates the effects of brodifacoum, a common poisonous substance found in rat and mouse bait on horses. The results showed significant changes in blood clotting times, drop in blood cells, and weight loss among other symptoms, indicating that horses may suffer severe toxic effects from brodifacoum.

Research Methodology

  • In this experiment, a total of six horses were used.
  • They were given brodifacoum (BDF)-containing bait at a dose of 0.125 mg of BDF per kg of body weight.
  • The condition of the horses was then closely monitored and observations were recorded.

Results and Observations

  • All six horses showed weight loss, serious hypocoagulability (lack of ability for the blood to clot), and alterations in their hemograms (blood tests).
  • Four horses became depressed and lost their appetite.
  • There were increases in clotting times. This was first observed 24 hours post ingestion in the partial thromboplastin time (PTT), followed by the thrombotest (TBT) at 48 hours, and finally in one-stage prothrombin time (PT) by day 2.
  • Between days 4 to 8, the PTT, PT and TBT were significantly higher. During this time, the maximum prolongation observed was a fourfold increase in PTT (day 4), a 2.5-fold increase in TBT (day 6), and a twofold increase in PT (day 6). Thrombin clotting times remained unchanged throughout.
  • In two of the horses, clotting time did not normalize until day 23.
  • Other significant findings were a decrease in mean hematocrit, hemoglobin concentration, and erythrocyte numbers from days 6 to 14 and in platelet counts from day 6 to 9.

Toxicokinetics

  • Peak plasma concentrations of BDF were detected between 2 to 3 hours after oral administration.
  • In two cases, BDF was detected in the horses even nine days after ingestion.
  • The estimated half-life of BDF in the horses was 1.22 +/- 0.22 days, showing a relatively quick turnover of the compound.
  • BDF has a body clearance of 1073.1 +/- 53.21 mL/kg/day and a volume of distribution of 1853.7 +/- 26.41 ng-day/mL.
  • The study also shows that the elimination phase of BDF approximates a one-compartment model.

Conclusion

  • The study provides critical insights into the toxic effects of brodifacoum in horses and can be extremely important for horse owners, vets, and others involved in equine care.
  • The research points out the dangers posed by brodifacoum ingestion, highlighting the need for caution with such substances around horses.

Cite This Article

APA
Boermans HJ, Johnstone I, Black WD, Murphy M. (1991). Clinical signs, laboratory changes and toxicokinetics of brodifacoum in the horse. Can J Vet Res, 55(1), 21-27.

Publication

Canadian journal of veterinary research = Revue canadienne de recherche veterinaire
ISSN: 0830-9000
NlmUniqueID: 8607793
Country: Canada
Language: English
Volume: 55
Issue: 1
Pages: 21-27

Researcher Affiliations

Boermans, H J
  • Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph.
Johnstone, I
    Black, W D
      Murphy, M

        MeSH Terms

        • 4-Hydroxycoumarins / pharmacokinetics
        • 4-Hydroxycoumarins / toxicity
        • Animals
        • Anorexia / chemically induced
        • Anorexia / veterinary
        • Blood Coagulation / drug effects
        • Erythrocyte Count / drug effects
        • Erythrocyte Count / veterinary
        • Female
        • Hematocrit / veterinary
        • Hemoglobins / analysis
        • Hemoglobins / drug effects
        • Horse Diseases / chemically induced
        • Horses
        • Male
        • Platelet Count / drug effects
        • Platelet Count / veterinary
        • Rodenticides / pharmacokinetics
        • Rodenticides / toxicity
        • Weight Loss / drug effects

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        Citations

        This article has been cited 4 times.
        1. Bagardi M, Drago G, Ferrari PL, Riva J, Moioli M. Acute severe pericarditis secondary to rodenticide intoxication in a dog.. Open Vet J 2022 Sep-Oct;12(5):728-734.
          doi: 10.5455/OVJ.2022.v12.i5.18pubmed: 36589411google scholar: lookup
        2. Romano MC, Francis KA, Janes JG, Poppenga RH, Filigenzi MS, Stefanovski D, Gaskill CL. Determining an approximate minimum toxic dosage of diphacinone in horses and corresponding serum, blood, and liver diphacinone concentrations: a pilot study.. J Vet Diagn Invest 2022 May;34(3):489-495.
          doi: 10.1177/10406387221086923pubmed: 35369800google scholar: lookup
        3. Zakian A, Mami S, Nouri M, Jalali SM, Tehrani-Sharif M. Brodifacoum toxicosis and abortion in an Arabian mare.. Vet Res Forum 2019 Spring;10(2):173-176.
          doi: 10.30466/vrf.2018.85534.2115pubmed: 31338153google scholar: lookup
        4. Ayala I, Rodríguez MJ, Martos N, Zilberschtein J, Ruíz I, Motas M. Fatal brodifacoum poisoning in a pony.. Can Vet J 2007 Jun;48(6):627-9.
          pubmed: 17616062
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